[mysql] more tuning/compatibility backports for AR 4.2 (working boolean emulation)

de-ja-vu fixes boolean type columns #626 
(were not working when emulation changed at runtime due missing type map reload on cache clear)

Author: kares

lib/arjdbc/mysql/adapter.rb

@@ -202,7 +202,16 @@ def quote(value, column = nil)
       else
         super
       end
-    end
+    end unless AR42
+
+    # @private since AR 4.2
+    def _quote(value)
+      if value.is_a?(Type::Binary::Data)
+        "x'#{value.hex}'"
+      else
+        super
+      end
+    end if AR42
 
     # @override
     def quote_column_name(name)
@@ -254,6 +263,10 @@ def supports_rename_index?
       (version[0] == 5 && version[1] >= 7) || version[0] >= 6
     end
 
+    def index_algorithms
+      { :default => 'ALGORITHM = DEFAULT', :copy => 'ALGORITHM = COPY', :inplace => 'ALGORITHM = INPLACE' }
+    end if AR42
+
     # @override
     def supports_transaction_isolation?(level = nil)
       version[0] && version[0] >= 5 # MySQL 5+
@@ -376,7 +389,7 @@ def indexes(table_name, name = nil)
     # Returns an array of `Column` objects for the table specified.
     # @override
     def columns(table_name, name = nil)
-      sql = "SHOW FULL COLUMNS FROM #{quote_table_name(table_name)}"
+      sql = "SHOW FULL #{AR40 ? 'FIELDS' : 'COLUMNS'} FROM #{quote_table_name(table_name)}"
       columns = execute(sql, name || 'SCHEMA')
       strict = strict_mode?
       pass_cast_type = respond_to?(:lookup_cast_type)
@@ -683,6 +696,18 @@ def valid_type?(type)
       ! native_database_types[type].nil?
     end
 
+    def clear_cache!
+      super
+      reload_type_map
+    end if AR42
+
+    # @private since AR 4.2
+    def prepare_column_options(column, types)
+      spec = super
+      spec.delete(:limit) if column.type == :boolean
+      spec
+    end if AR42
+
     # @private
     Type = ActiveRecord::Type if AR42
 
@@ -817,6 +842,7 @@ def full_version
 
     # @private
     def emulate_booleans; ::ArJdbc::MySQL.emulate_booleans?; end # due AR 4.2
+    public :emulate_booleans
 
     # @private
     class MysqlDateTime < Type::DateTime
@@ -879,9 +905,9 @@ def adapter
 
       end
 
-      def initialize(*args)
-        super # configure_connection happens in super
-      end
+      #def initialize(*args)
+      #  super # configure_connection happens in super
+      #end
 
       def jdbc_connection_class(spec)
         ::ArJdbc::MySQL.jdbc_connection_class

test/db/mysql/simple_test.rb

@@ -50,9 +50,9 @@ def test_time_usec_formatting_when_saved_into_string_column
   column_quote_char "`"
 
   def test_column_class_instantiation
-    text_column = nil
     assert_nothing_raised do
-      assert text_column = mysql_adapter_class::Column.new("title", nil, "text")
+      text_column = mysql_adapter_class::Column.new("title", nil, "text")
+      assert text_column.is_a?(ActiveRecord::ConnectionAdapters::Column)
     end unless ar_version('4.2')
   end